The only A3 to get a five-door wagon layout, this plug-in hybrid Audi might be one of the best-driving PHEVs we've ever seen.

Sometimes the best tech is what disappears into the background. A quick look at the A3 e-tron prototype suggests Audi understands the power of understatement. While EV prototypes such as the Cadillac ELR and BMW i3 look radical inside and out, practically smacking you in the face with their futuristic feel, the Audi feels much more like a conventional A3. After some time behind the wheel, you forget you're driving a plug-in and simply enjoy the ride.

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The conventional Audi A3 will arrive in the U.S. as a sedan, a convertible, and a high-performance S3 model. But none of them will use the five-door wagon body—that silhouette is saved for the A3 e-tron. The A3 e-tron (e-tron will be Audi's catchall subbrand for electrified mobility) uses a strengthened version of the same 150-hp, 1.4-liter turbocharged four-cylinder found in the Jetta Hybrid. This engine is mated to a unique double-clutch DSG transmission that incorporates a 75-kw electric motor within its case. The entire system produces 204 hp and 258 lb-ft of torque. That's enough to hit 60 mph in around 7.6 seconds. To keep the e-tron quiet, Audi uses the heavier noise suppression materials found in diesel A3 models.

The 8.8-kwh Panasonic lithium-ion battery pack sits in an aluminum enclosure protected by a carbon-fiber skidplate, and installs under the rear seats, where the gas tank would be on a conventional A3. The new, smaller 10.6-gallon fuel tank rides underneath the cargo floor in the trunk. The combination is enough to provide around 25 miles of electric-only range and up to 580 miles of hybrid operation. Charge time on a 240-volt is said to be around 2 hours. All the additional equipment adds about 720 pounds to the weight of a conventional A3, so the e-tron tips the scales at just over 3400 pounds. Unfortunately the new powertrain leaves no room for Quattro—all A3 e-trons will be front-drive.

The electric motor's thrust runs through the transmission, so you'll get stepped gear changes in pure EV mode, providing a seamless rush of torque. In hybrid mode, it's fun to ride that torque wave through a set of switchbacks. And that's the best part about the e-tron: It handles like any other Audi. Bend it into a corner and the car feels composed, capable, and fun. This might be one of the best driving plug-in hybrids we've ever encountered.

So what's the slickest feature of the A3 e-tron? Push and slide the four-ring Audi badge on the nose of the e-tron to the side to reveal the electrical charge port. It's perhaps the coolest integration of a charging port on any EV. Like many other battery-electric cars today, Audi will have a connectivity phone app that will allow owners to precondition the cabin and set up specific charging times.

Europe will get these cars in 2014, but Audi stores in the U.S. won't see them until mid-2015. That may be a long time, but it's worth the wait.